Today huge amounts of data are available in libraries, archives and databases. Digitalization and metadata, i.e. data about data, have simplified the use of these data. During digitization or content analysis different metadata extracting methods are used to extract and save these metadata to an internal metadata repository. With the help of metadata, the underlying data can be accessed efficiently. However, with the increasing number of available methods for extracting metadata, the amount of metadata in the repositories increases accordingly. This enormous increase of metadata amount somewhat decreases the efficiency for data access. How to raise the metadata quality has thus become more and more important. The daily increasing amount of digital audio and video content poses new challenges for content management systems in digital film and video archives. Therefore, authoring tools that can access and edit audio and video content efficiently are required. One approach for tackling the problem is the description of the contents of the audio and video files with the help of semantically linked metadata, and the use of this type of metadata for effective management of the huge data sets. Browsing through content or search and retrieval of specific content can be realized very efficiently by applying semantically linked metadata. Semantically linked metadata is a kind of qualified metadata. Also various types of recommendations for similar content can be realized with semantically linked metadata.
Nonetheless, also with semantically linked metadata there the overall amount of metadata associated to an audio or video file is too large for certain applications. For example, for the semantic annotation and linking work for a video file archivists would prefer to have a tool that can efficiently limit the amount of metadata that is presented. To give an example, a face detection algorithm detects all faces in a video regardless of how relevant the detected faces are for a semantic description of the content. Typically, in a news program roughly about 5% of the detected faces are relevant for the semantic annotation and linking work. Therefore, it would greatly increase the efficiency and usability of a manual semantic annotation and linking tool if only the relevant elements were presented to the user in a graphical user interface. A key aspect of such a tool is hence a prioritization of semantic metadata regarding their probable relevance to the semantic description of the video data.
A solution for prioritizing metadata has been proposed in European Patent Application 11306747.4, where prioritization values are automatically determined by combining specific characteristics of independently generated semantic metadata. According to this solution, a method for determining priority values of metadata items of a first set of metadata items associated to a video data item, the first set of metadata items being of a first type, comprises the steps of:                retrieving the first set of metadata items;        retrieving a second set of metadata items associated to the video data item, the second set of metadata items being of a second type different from the first type;        calculating one or more of a plurality of predetermined priority variables for the first set of metadata items, wherein the one or more priority variables are calculated from metadata items of the first set of metadata items and metadata items of the second set of metadata items;        performing an analysis of the one or more priority variables; and        determining the priority values of the metadata items of the first set of metadata items based on results of the analysis of the one or more priority variables.        
In order to prioritize the metadata, priority variables are used. These priority variables are calculated from the different types of metadata and/or from relationships between the types of metadata. Once the priority variables have been determined, they are analyzed to automatically classify the metadata items into different categories, e.g. important and non-important. The final priority value for each metadata is thus represented by a flag, i.e. essentially by an integer value.